Studies using the mouse model of the fetal alcohol syndrome are continuing. The minimum number of days of prenatal alcohol exposure required to obtain malformations associated with the mouse syndrome will be investigated, as will the minimum period of abstinence required for normal fetuses, from female mice previously exposed to chronic alcohol treatment. To determine the role of alcohol and acetaldehyde metabolism on risk determination, three strains of mice with differing susceptability to the fetal alcohol syndrome will be investigated. Finally, a histologic study of embryogenesis in normal mice and those affected with the syndrome will be completed.